The 2010 midterm elections did not go well for President Obama or Democrats. With Republicans taking control of the House and the Democratic majority having been significantly narrowed in the Senate, the administration will not have much luck working with Capitol Hill.

Although some commentators see an opportunity for bipartisan compromise, after the experience of the past two years, when Washington looked more like a steel-cage wrestling match than a forum for rational deliberation, there is little reason to believe that the parties will find any areas of agreement. Before the election, Senator Minority Leader Mitch McConnell already declared, “The single most important thing we want to achieve is for President Obama to be a one-term president.”

Experts will spend a long time trying to sort through the various causes behind the outcome. It will be difficult to determine exactly which factors, some local, some national, and some having to do with the particularities of candidates, were the most important.

But what we do know already is that the elections have reshaped the legislative playing field for President Obama. That’s what midterms can do. His administration will now have to survive a divided Congress where conservatives will be able to shape deliberations since they control the House and since the size of their minority in the Senate will make it virtually impossible for Democrats to push through any bill that does not command some Republican support. It could very well be that the 2010 midterms have reversed the results of 2006 when Democrats had finally regained control over the legislative process. The question is how lasting the impact will be.

Historically, certain midterms have had major effects on the legislative landscape. One party does not even need to win control of Congress to have this effect. One of the most important took place in Franklin Roosevelt’s second term. In 1938, Roosevelt’s domestic agenda came to a crashing halt when the conservative coalition of Southern Democrats and Republicans expanded their numbers in the House and Senate. Following his landslide victory in 1936, Franklin Roosevelt had triggered a political backlash as a result of his court-packing and executive reorganizations plans. Members of FDR’s administration perceived the primaries as an effort by “reactionaries” to subvert liberalism. “The Democratic Party is... engaged in a great struggle against reaction within the party as well as without the party. Reactionaries within the party,” Secretary of Interior Harold Ickes wrote Congressman Maury Maverick, “are attempting to gain control of the party in order to destroy the party’s devotion to the great liberal principles….”

Trying to avert this outcome, FDR campaigned in the primaries to purge eight conservatives from the Democratic Party. The president went so far as to confront Georgia Senator Walter George while appearing with him at a public event in his district. Urging the audience to vote for George’s opponent, Roosevelt said that, “the senior Senator from this State, cannot possibly, in my judgment, be classified as belonging to the liberal school of thought….”

But the elections didn’t go well for FDR. Seven of the eight Democrats who FDR tried to purge were victorious. They came back Washington doubly determined to cause him problems. Republicans achieved sizable gains in the House and Senate while in several southern states conservatives replaced New Deal liberals. The conservative coalition emerged from the midterms vastly strengthened and prepared to use the committee process as well as their votes on the floor to stifle as many of FDR’s initiatives as possible. The coalition would remain a potent political force for the next three decades.

Another hugely consequential midterm election took place in 1966 when Republicans won 47 seats in the House and four seats in the Senate. Republicans had campaigned by focusing on Lyndon Johnson’s failed strategy in Vietnam, warning of the dangers of inflation, and tapping into a racial backlash against civil rights. The conservative coalition, which had been emasculated in 1964, exited from the midterms revived. Johnson was severely constrained in the final two years of his presidency. Several Republicans, moreover, who were planning to run for president in 1968 had their careers bolstered by the results, including Richard Nixon, who campaigned for many candidates across the country, and Ronald Reagan, who won the gubernatorial race in California and became the first candidate associated with the right wing to win a major executive office.

Although Johnson later dismissed the results as a natural dynamic that always followed an election as sweeping as that of 1964 (he compared it to the elections of 1938 and 1958), the president privately knew the immense consequences this election would have. The cover of Time magazine featured six smiling Republicans. House Majority Leader Carl Albert said that the elections “broke the back of the Great Society right there... Thus fortified, [Republicans] proceeded to turn back new initiatives and reduce old ones to sepulchers haunted with dead promises of what might have been.”

Not all midterms have as lasting a consequence on Congress. The 1946 midterms were very damaging to Democrats in the short-term. The GOP ran a campaign that accused Democrats of being too soft on communism and for having imposed excessive controls on the economy during the war.

The results were interpreted as a mandate for conservatism. New Hampshire Republican Senator Styles Bridges boasted, “The United States is now a Republican country.” The Republican numbers in the Senate went from 38 to 51, and in the House from 191 to 246, a stunning defeat for many Democrats. President Harry Truman felt immense pressure to shift to the right, including on issues such as national security.

But the results were overturned two years later when Democrats regained control of Congress in the 1948 election, including a gain of 75 seats in the House. The election brought in a new generation into Congress, such as Paul Douglas of Illinois and Hubert Humphrey of Minnesota—who called on his party to “get out of the shadow of states’ rights and walk forthrightly into the bright sunshine of human rights”—as well as Lyndon Johnson of Texas, who would remake the party and push their party into new frontiers including civil rights and health care.

It remains unclear what kind of long-term effect the 2010 midterm election will have on the legislative landscape. Republicans hope that that the midterm will be more like 1938 and 1966, a lasting turning point, and that their party is now beginning to reclaim the position that they lost in Congress during the past four years. For Democrats, their hope is that the 2010 election was more like 1946, just a temporary setback that can be reversed with the next election cycle.

Julian E. Zelizer is professor of history and public affairs at Princeton University. He is the author and editor of 11 books. His most recent publications include Jimmy Carter (Times Books), Arsenal of Democracy (Basic Books), The Presidency of George W. Bush (Princeton Univ. Press), and Conservatives in Power (Bedford Books). Zelizer, who appears regularly in the media, has published over 200 op-eds.